That is precisely the contract violation I'd like to see reported, but, without the shadowing of serialize and deserialize, the error is reported in terms of `+`. (And, if it wasn't clear, I do intend to actually read and write the serialized instance.)
I (think) I understand why deserialization strips the contract from the instance: the contract is added at the module boundary using the chaperone/impersonator infrastructure, and deserialization uses the unprotected form of `adder` passed to `make-deserialize-info` within the server module. What I don't understand is how to give `make-deserialize-info` a function that (1) has a contract where (2) fulfilling the range part of the contract becomes the deserializing module's obligation — if such a thing is possible. Aside from attempts with `define/contract` (which as I now understand achieved point 1 but not point 2), I've also tried putting the definition of `deserialize-info:adder-v0` in a different module, so that its version of `adder` has a contract, but then the binding isn't seen by `make-serialize-info`. -Philip On Mon, Jul 24, 2017 at 7:30 AM, Matthias Felleisen <matth...@ccs.neu.edu> wrote: > > On Jul 23, 2017, at 10:50 PM, Philip McGrath <phi...@philipmcgrath.com> > wrote: > > If I'm following correctly, I think that's what I was trying to do, but > I'm unclear how to give `make-deserialize-info` a variant of `make-adder` > that has a contract. The initial example with `define/contract` was the > closest I've come: it at least reported violations in terms of `make-adder` > rather than `+`, but (as I now understand) it blamed the `server` module > for all violations. > > -Philip > > On Sun, Jul 23, 2017 at 9:27 PM, Matthew Flatt <mfl...@cs.utah.edu> wrote: > >> The original example had an explicit deserializer: >> >> At Sun, 23 Jul 2017 19:54:43 -0500, Philip McGrath wrote: >> > (define deserialize-info:adder-v0 >> > (make-deserialize-info make-adder >> > (λ () (error 'adder >> > "can't have cycles")))) >> >> You're constructing the deserializer with `make-adder` --- the variant >> from inside the `server` module, so it doesn't have a contract. >> >> I think this is where you want to draw a new boundary by giving >> `make-deserialize-info` a variant of `make-adder` that has a contract. > > > > > Don’t you just want this: > > #lang racket > > (module server racket > (require racket/serialize) > > (provide (contract-out > [adder (-> natural-number/c (-> natural-number/c > natural-number/c))])) > > (struct adder (base) > #:property prop:procedure > (λ (this x) (+ (adder-base this) x)) > #:property prop:serializable > (make-serialize-info (λ (this) (vector (adder-base this))) > #'deserialize-info:adder-v0 > #f > (or (current-load-relative-directory) > (current-directory)))) > > (define deserialize-info:adder-v0 > (make-deserialize-info adder (λ () (error 'adder "can't have > cycles")))) > > (module+ deserialize-info > (provide deserialize-info:adder-v0))) > > (require (submod "." server) racket/serialize) > > (local ((define serialize values) > (define deserialize values)) > (define x (serialize (adder 5))) > (define f (deserialize x)) > (f 'not-a-number)) > > > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
